1. Field
The present invention relates to a heat dissipating device to dissipate heat generated by an electrical component in a computer system, and more particularly to a heat dissipating device which has a back plate for strengthening a printed circuit board in the computer system.
2. Prior Art
As computer technology continues to advance, electronic components such as central processing units (CPUs) of computers are made to provide faster operational speeds and greater functional capabilities. When a CPU operates at a high speed in a computer, its temperature frequently increases greatly. Therefore, a heat dissipating device is widely used to remove heat from a CPU of a computer. FIGS. 4-6 illustrate an electronic assembly including a conventional heat dissipating device for a CPU 2 of a computer. As shown, a printed circuit board 4 (PCB) has a top side provided with an integrated circuit socket 3 for establishing electrical connection with the CPU 2. The heat dissipating device comprises a heat sink 1 attached to the CPU 2. The heat dissipating device further comprises a back plate 5 disposed below the printed circuit board 4 for mounting of the heat sink 1 and strengthening the printed circuit board 4 to reduce a deformation thereof. Bolts 6 are extended through the heat sink 1, the printed circuit board 4 and the back plate 5, and respectively threadedly engaged with nuts 7, respectively. The electronic assembly including the heat dissipating device is thus fixed together.
However, as shown in FIG. 5 and FIG. 6, since the back plate 5 is formed of a thin metal sheet and the heat sink 1 is made larger and larger (which means heavier and heavier), the conventional back plate 5 is no longer strong enough to strengthen the printed circuit board 4 to stand a weight of the heat sink 1 acting on the CPU 2 and accordingly the PCB 4. As a result, a portion of the printed circuit board 4 below the CPU 2 is deformed downwardly as shown in FIG. 6, which shows the deformation in an exaggerative manner. Such a deformation may adversely affect electrical connection between the CPU 2 and the printed circuit board 4. Furthermore, since the back plate 5 is not foldable, to transport or store it needs a large space.
Consequently, there is a need in the art to provide a back plate which can sufficiently strengthen the printed circuit board and which is foldable.